#SGHaze explained

Current and historic PSI readings

View the current 24-hour and 3-hour PSI reading for each region of Singapore and explore how the 24-hour PSI has been trending since Sept 1, 2015. The current PSI provided by NEA reflects the total levels of six pollutants in the air we breathe; sulphur dioxide (SO2), particulate matter (PM10), fine particulate matter (PM2.5), nitrogen dioxide (NO2), carbon monoxide (CO) and ozone (O3).

Tracking fires in South East Asia

The forest and plantation fires in Central Kalimantan and South Sumatra are the main cause of the haze in Singapore. Fires are caused by the slash and burn method which is a farming technique used to clear forested land. Here is a real-time look at the hotspots in the region using NASA’s database over the last 24 hours.

NASA measures the temperature of the fire - the darker the colour of the hotspot, the higher it’s temperature. Some of the hottest fires can reach up to 84 degrees celsius.

CONFIDENCE LEVEL

NASA uses satellite imagery to detect hotspots and a confidence index to help show the accuracy of the data. The index is out of 100, so a hotspot with an index of 100 is a confirmed fire. A smaller value means the hotspot's location or temperature cannot be completely verified or is subject to change.

A smouldering problem

Haze from Indonesian forest fires has shrouded Singapore skies for days. Some have identified fires burning on degraded peatlands and idle scrubland in the province of Riau, Sumatra as the main contributors to the haze affecting Singapore and Malaysia. The Straits Times looks at what a peat fire really is.